G—CSF对大鼠脊髓损伤后神经细胞凋亡及caspase-3表达的影响

目的：通过观察粒细胞集落刺激因子（G—CSF）对大鼠急性脊髓损伤后神经细胞凋亡及Caspase-3的表达的影响，探讨其对脊髓保护的作用机制。方法：32只Vistar大鼠随机分成2组：对照组和治疗组，每组16只，采用改良的Allen’s装置制成大鼠急性脊髓损伤模型。在术前及术后对大鼠进行BBB功能评分观察大鼠的神经功能变化；用免疫荧光法检测脊髓损伤后个时间点Caspase-3表达；原位脱氧核糖核苷酸末端转移酶介导的缺口末端标记法（Tunel法）检测凋亡细胞。结果：大鼠急性脊髓损后Caspase-3表达与细胞凋亡均呈现先升高后下降的趋势，损伤后3d可见大量的Caspase-3和TUNEL阳性细胞，7d时达到高峰，此后表达逐渐减少，21d时仍可见少量阳性细胞。与对照组比较，G—CSF治疗组各时间点Caspase-3表达和细胞凋亡显著降低，功能恢复显著优于对照组，差异具有统计学意义。结论：G-CSF可以减轻大鼠脊髓损伤后的神经元凋亡，从而发挥神经保护作用，其作用可能是通过抑制Caspase-3的表达使脊髓损伤周围神经细胞凋亡显著下降而实现的。

Effect of Granulocyte Colony-stimulating Factor on Changes of Neuronal Apoptosis and Caspase-3 Expression after Spinal Cord Injury in Rats

Objective： To investigate the effect of Granulocyte colony-stimulating factor on changes of neuronal apoptosis and expression of caspase-3 after spinal cord injury and to explore its protective effect and actionmechanism. Methods： 32 Vistar rats were divided into two groups by randomization： Sham and G-CSF cure groups, there were 16 rats in each group. Vistar rat model of acute spinal cord injury were established by modified Allen＇s device. The hind limb Neurologica function of the rats was evaluated by BBB score. The terminal deoxynucleotide transferase mediated DUTP- biotin nick end labeling （TUNEL） and Immunofluorescence measurement were used to observe neural apoptosis and expression of Bcl-2 and Bax proteins. Results： After spinal cord injury, Caspase-3 expression and apoptosis showed a downward trend after the first elevated. 3d after injury can be seen a lot of Caspase-3 and TUNEL-positive cells, and reached its peak at 7d, after which expression gradually reduced. A small amount of positive cells still appeared at 21d. Compared with the control group, G-CSF treatment group at different time points Caspase-3 expression and apoptosis decreased singnificantly.Neurological fimctional recovery in rats was significantly better than the control group. The difference was statistically significant. Conclusion： G-CSF could exert neuroprotection through reduction in neuronal apoptosis in rat acute spinal cord injury. Its role may be through upregulating the expression ofbcl-2 protein and reducing the expression ofbax proten may decreased cell apoptosis significantly in peripheral nerve after acute spinal cord injury.